Bore-safe fuse



May 24, 193s.

D. L. WOODBERRY BoRE SAFE FUSE Filed sept. 21, 1937 INVENTOR.

.Dev/'af 1l. Woodberry' -WMQ M I ATTORNEY.

ias

Patented May 24, 1938 BORE-SAFE FUSE David L. Woodberl'y, Perryman, Md.Application September 21, 1937, Serial No. 164,915

.s claims.

' (Granted under theact o! March 3, 1883, as amended April 30, 1928; 3700. G. 757) .The invention described herein may be manufactured and usedby or for the Government for governmental purposes, without the paymentto me of any royalty thereon.

This invention relates in general to actuating mechanisms andmoreparticularly has reference to an all-ways, bore-safe fuse.

Previous to this time in fuses of this character,

. it has been customary to positively lock a tiring pin out of contactwith an aligned primer and auxiliary booster charge, the primer andauxiliary booster charge being aligned at all times. A fuse of thischaracter is not bore-safe, and does not l permit its assembly to ashell'to make a complete round until ready to i'lre, andthen extremecare in handling and iirlng should be exercised. It will be apparentthat a fuse of this character tends to complicate handling and storagein that the fuse has to be stored and shipped separate from the shelland bursting charge proper.

An object of this invention is to provide an allways, bore-safe fusehaving a ring pin positively locked out of contact with an aligneddetonator before ejection from the muzzle of the piece from which it maybe red.

Another object of this invention is to provide an all-ways, bore-safefuse having a detonator carrier adapted to interrupt the explosive trainand containing a detonator therein out of alignment with the saidexplosive train adapted 30 to be released for alignment therewith ontiring` and to align after ejection from the muzzle of the piece fromwhich it may be fired.

Still another object of kthis invention is to provide an all-ways,bore-safe fuse having a detonator carrier normally out of alignment withthe explosive train prior to ejection from the muzzle of the piece fromwhich it may be red, adapted to be aligned therewith and locked in placeafter 40 being ejected from the muzzle of the piece from i which it maybe iired.

A further object of this invention is to provide an all-ways, bore-safefuse having a U-shaped safety fork, one leg of which is adapted to lock5 the firing pin out of contact with the detonator aligned therewith andthe other leg is adapted to hold the detonator carrier ih a position tointerrupt the explosive train and hold the detonator contained thereinout of alignment therewith 50 previous to firing from the piece.

It will thus be apparent that the objects of this invention are ingeneralhto provide an al1-ways, bore-safe fuse having a slidabledetonator carrier and a ring pin having a common arming 55 featureadapted to become armed after ejection from a weapon, and the ring pinto set oii`.the explosive train upon impact with the ground regardlessof the angle the fuse strikes the ground.

With these and other objects in view which may be incident to myimprovements, the invention consistsvin the parts and combinations to behereinafter set forth andclaimed, with the understanding that theseveral necessary elements comprising my invention may be varied inconstruction, proportions and arrangement, without departing from thespirit and scope of the appended claims. i

In order to make my invention more clearly understood, I have shown inthe'accompanying drawing means for carrying the same into practicaleffect, without limiting the improvements in their useful applicationsto the particular constructions, which for the purpose of explanation,have been made the subject of illustration.

In the drawing forming a part of this application: l

Figure 1 is a longitudinal sectional view of the fuse fully loadedbefore assembling to a shell.

Figure 2 is a, sectional view of the fuse taken on line 2-2 of Figure 1.

Figure 3 is a longitudinal sectional view of the fuse assembled to ashell being ejected from the muzzle of a piece.

Figure 4 is a longitudinal sectional view of-the fuse and shell inflight after ejection from the muzzle of the Weapon.

Referring more particularly by numerals to the drawing in which the sameand similar elements are designated by like symbols of referencethroughout, and more particularly to Figure 1, there is shown anintegral fuse body I formed at the top with a truncated head portion 2and at the bottom with a downward projecting neck 3. The mid-section ofthe body is provided' with a vertical bore 5 of larger diameter land ahorizontal aperture 6. The bore 4 is closed at one end with a screw capand open into one face of the fuse body at the other through acnstricted bore while the bore 5 opens into the nose of the head at oneend and is closed with another screw cap and the other end of restricteddiameter communicates with the bore 4. One end of the horizontalaperture 6 communicates with the vertical bore 5 and opens into one faceof the fuse head at the other.

The neck is provided with a vertical Ybore l, opening. in the bottomthereof at one end, and

communicating at the other with a smaller bore -8 opening into thehorizontal bore 4, the same corresponding with and being in alignmentwith 55 the vertical bore l opening into the other side thereof. Theneck of the fuse is provided in addition with a vertical bore 9 locatedbetween the bore 1 and the outer wall of the neck.

Ailringpin I9 is adapted totintothevertical bore l. "The top portion o fthe ring pin is provided with a ball-shaped head. 'I'he ballshaped headis adapted to nt into a cone-shaped socket provided in the screw cap' Ilwhichcloses one end of the vertical bore 9. A sleeve I2 is also adaptedto fit into the vertical bore l9,having a horizontal bore I4. The topend of the vertical bore I3 is adapted to have the ring pin I9 fittedtherein, whereas the bottom end of the bore i9 is provided with a primerdetonator I I. A spring I9 is adapted to fit around the firing vpin I9between the head of the firing pin and the top of the sleeve therebyforcing the head of the firing pin into the cone-shaped socket in thescrew cap II and at the same time forcing the bottom of the sleeve I2into the cone-shaped bottom of the vertical bore 5.

Adetonator carrier `i1 having a vertical aperture formed in one endthereof and extending therethrough for carrying a detonator I9, ismounted in the horizontal bore 4. After insertion of the detonatorcarrier in the bore 4, the bore 4 is closed by a screw cap I9, fitted inthe seat 2li forming an extension of the bore 4 and communicating withthe outer portion of the fuse head 2.

The detonator carrier I1 is provided with a longitudinal groove 2|(Figure 2) on one side thereof. At right'angles to the bore 4, the fusebody is provided with a bore 22 extending into a bore 23 of enlargeddiameter communicating with the outer portion of the fuse head. A screw24 is fixed in the bore 23, having an extension 2i of constricteddiameter extending through the bore 22, and fitting in the groove 2i',formed in the detonator carrier I1 to prevent rotation thereof.

The U-shaped lsafety fork 29 is adapted to fit in the bores 6 and 21extending vfrom the bores 4 and 5. One end of the fork passes throughthe horizontal bore I4 of the sleeve I2 between the bottom of the firingpin I0 and the top of the primer-detonator I5, thereby locking thefiring pin out of contact with the primer-detonator aligned therewith.The other end passes through the bore 21 into the bore 4 and holds thedetonator carrier in the unarmed position against the action of thespring 28 until after the fuse is fired from the piece.

Movement of the U-shaped safety fork is prevented by a' set-back pellet29, as shown in Figure 1, seated in the vertical bore 9. The pellet 29is provided with an integral extension 30, adapted y to fit in a slot3|` in one end of the safety fork 26. The extension 30 is held in theslct 3I by a spring 32 in the bore 9 which is seated on a screw plug 33.Movement of the pellet 29 is prevented by a safety pin 34 which passesthrough the body of the fuseand the pellet. The removal of the safetypin is facilitated by a pull ring 35 as shown in Figure 2, fastenedthereon.

The bores 1 and 8 in the neck of the fuse are adapted to contain anauxiliary booster charge 36. vThe bore 8 is closed at the top with athin metal cup 31, and the bore 1 is closed at the bottom with a screwcap 38 which retains the auxiliiary booster charge.

The operation of the invention will be readily understood by firsthaving reference to Figures 3, 4 and 5.

a,11s,oes Y, L

when le a desi-d to nre a projectile having" the fuse forming thesubject matter of this invention assembled therein, asshown in Figure 3,the safety pin 94 is removed, freeing the set-back pellet 29. Theprojectile is then inserted in the barrel of a weapon. movement of thesafety fork being prevented as shown in Figure i by engagement of theextension 99 of the pellet 29 with the slot 9i therein. On firing theforcevof set-back incident to the combustion of the propellant charge isadapted to set-back the pellet 29 against the spring 92, compressing itso that the detonstor carrier and safety fork are released as shown inFigure 3. n

It wilibe apparent, with the set-backV pellet in the rearward position,the safety fork and detonator carrier are ,free to move outward underthe force of the spring 29, until the safety fork comes in contact withthe inside of the barrel 49 as shown in Figure 3.

After the projectile leaves the muzzle of the weapon, the spring 29 isadapted to move the detonator carrier over to the armed position' toalign the detonator'll with the primer-detonator I9' and the auxiliarybooster charge 99, Concomitantly with movement of the detonatorcarrierto the armed position, the safety fork is ejected from the bodyof the fuse by the action of the spring 29 and falls away into the airthereby leaving the firing pin free to function the primer-detonator Il-on impact with the target as shown in Figure 5. l

'I'he detonator carrier I1 is locked in the armed position by engagementof the extension 90 of the pellet 29 in the aperture 99 in the detonatorcarrier I1 as shown in Figure 4 when the shell is in flight.

Figure 4 snows the projectile in night with the fuse in the armed 'andlocked position ready to function upon impact with the target.

On impact with the target the firing pin engages with and sets ofi' theprimer-detonator, causing the detonation of the auxiliary booster chargeand bursting charge proper in the shell.

There is accomplished by this invention an allways, bore-safe fuse forsmooth bore pieces having a detonator carriernormally held in theunarmed position by a U-shaped safety fork adapted to arm. and loclrvink the firing position while in trajectory after it is fired from themortar.

While I have shown and described the preferred embodiment of myinvention, I wish it to be understood that I do not confine myself tothe precise details of construction herein set forth by way ofillustration as it is apparent that many changes and variations maybemade therein, by those skilled in the art, without `departing from thespirit of the invention, or exceeding the scope of the appended claims.

I claim:

, 1. A safety impact fuse for shells comprising a fuse body, a primercharge, a firing pin in alignment with said primer charge, atransversely movable member carrying a detonator charge, a safe- 3. Theinvent-.ion as desmbed in claim 1 wherein said last-named means includesa latch for said fork released by set-back of the shell.

4. The invention as described in claim 1 wherein said last-named meanscomprises a. latch for said fork released by set-back of the shell, aportion of the fork then engaging the interior wall of the gun barrel.

5. A safety impact fuse for shells comprising a body, a primer charge,and a booster charge in alignment but separated from one another, atransversely movable member carrying a detonator charge, a ring pin inalignment with said primer charge, a safety fork having a partinterposed between said ilring'pin and primer charge and a part holdingsaid transversely movable member with its detonator charge out ofalignment with said booster charge, set-back releasable means forretaining said fork in safe position, and means to retain said fork insafe position until the shell leaves the gun barrel.

6. A safety impact fuse for shells comprising a body, a primer chargeand a booster charge in alignment but separated from one another, amember carrying a detonator charge, a firing pin in alignment with saidprimer charge, a safety fork having two arms, one arm normally holdingthe detonator charge in unarmed position and the other arm normallyseparating the ring pin and primer charge, a latch retaining said forkin safe position, said latch being released upon setback oi' the shell,said fork being retained in safe position by engagement thereof with.the gun barrel, and means on the detonator charge carrying memberengageable by said latch to hold said detonator in armed position duringflight of the shell.

DAVID L. WOODBERRY.

